Monthly Archives: April 2014

“Despite aggressive efforts to control hemlock woolly adelgid infestations, large numbers of hemlock trees in the Southern Appalachian region are dead or in poor health. This loss has important implications. In addition to providing year-round cover for wildlife, hemlock has a strong influence on streamside habitat conditions and stream health. The shade cast by these majestic trees cools the water where brook trout and other stream organisms live; hemlock needles and wood decompose slowly, providing unique habitat for important forest floor organisms such as salamanders.”

“Many of these changes may prove to be short-term or localized; more significant changes are expected in the coming decades as other species replace hemlock. In areas where the evergreen shrub rhododendron is absent, red maple, sweet birch, and yellow poplar will probably take the place of eastern hemlock. Where rhododendron is already present, the shrub will probably spread, and could limit recruitment of overstory tree species.”

“Rhododendron, a woody evergreen shrub common in southern Appalachian forests, is one of the species replacing eastern hemlock trees. Although rhododendron is evergreen, it has lower leaf area than hemlock, and thus transpiration in rhododendron-dominated forest stands is lower than in previously-healthy hemlock forests. Most of the other species replacing eastern hemlock trees are deciduous, such as sweet birch, which unlike the evergreen rhododendron and eastern hemlock, do not transpire during the winter. Sweet birch trees also have a much higher transpiration rate than eastern hemlock trees during the growing season.”

“The Maryland Transportation Authority has installed a platform near the Anne Arundel County side of the William Preston Lane Jr. Memorial (Bay) Bridge in the hope that an osprey that had tried to build a nest in front of its traffic cameras there will take the hint and build her nest on the platform.”

“The Wissahickon is widely recognized for its majestic forests, rugged terrain, extensive trail system and other features. Perhaps a less-recognized aspect of the Park is the presence of a few meadows, most notably Houston Meadow. Houston Meadow, sometimes called Cathedral Meadow, consists of two areas: one immediately downslope of Houston Playground on Sequoia St. and another across the ravine to the north, near Clyde Lane.”

“Every day, thousands of cars and trucks rumble across bridges all over the U.S. Their drivers probably don’t give much thought to the fish swimming in the rivers, lakes or bays below. But the fish notice them: They can hear those noisy engines passing overhead, and according to a new study, they are having to shout to communicate over the din.”